Automatically modifying cell definition tables within networks

ABSTRACT

Systems and methods are described herein for modifying cell definition tables with telecommunications networks. In response to a handover failure between cells of the network, the systems and methods determine changes have been made to a network, such as changes to various identification information for cells associated with a controlling (or serving) node of the network. For example, the systems and methods utilize ANR functions to detect the changes to the network.

BACKGROUND

Automatic Neighbor Relation (ANR) functions in a telecommunicationsnetwork, such as a Long Term Evolution (LTE) network, enable operatorsto avoid manually managing neighbor relations (NRs) between cellsassociated with a controlling node, such as an eNodeB element of the LTEnetwork.

When user equipment (UE) attempts and fails a handover operation betweencells (e.g., from a source cell to a target cell), the physical cellidentity (PCI) information for the target cell is unknown to the ANRfunctionality. For example, when there is no neighbor relation table(NRT) that exists for the PCI (when the user equipment (UE) reportsphysical cell identity (PCI) information for the target cell, but thereported PCI is not mapped in the neighbor relation table (NRT) to anytarget nodes).

In conventional networks, the ANR functions request from the UE the cellglobal identity (CGI) for the target cell. The ANR then uses thereported CGI to build a new target cell identifier (TCI) for the targetcell, and updates neighbor relation tables (NRTs) within the controllingnode with the new TCI for the target cell.

However, in some cases, the NRT exists but the CGI of the target cellmay have previously changed during various network processes, such aspreviously performed network optimization processes. In such cases, ifthe CGI changes, but the PCI remains unchanged, the UE will report theunchanged PCI to the controlling node, which uses the CGI informationfrom the NRT. The controlling node, having the unchanged PCIinformation, will utilize corresponding TCI information, which iserroneous and obsolete (being associated with old CGI information).Thus, handover procedures to the target cell will fail, and the networkwill provide users with a low-quality experience, such as droppedconnections, among other drawbacks.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present technology will be described and explainedthrough the use of the accompanying drawings.

FIG. 1 is a block diagram illustrating a suitable computing environmentfor modifying cell definition tables with telecommunications networks.

FIG. 2 is a block diagram illustrating various modules of a tablemodification system.

FIG. 3 is a flow diagram illustrating a method for modifying celldefinition tables for a telecommunications network.

FIG. 4 is a flow diagram illustrating a method for determining changesto a telecommunications network using automatic neighbor relation (ANR)functionality.

The drawings have not necessarily been drawn to scale. Similarly, somecomponents and/or operations may be separated into different blocks orcombined into a single block for the purposes of discussion of some ofthe embodiments of the present technology. Moreover, while thetechnology is amenable to various modifications and alternative forms,specific embodiments have been shown by way of example in the drawingsand are described in detail below. The intention, however, is not tolimit the technology to the particular embodiments described. On thecontrary, the technology is intended to cover all modifications,equivalents, and alternatives falling within the scope of the technologyas defined by the appended claims.

DETAILED DESCRIPTION

Overview

Systems and methods are described herein for modifying cell definitiontables with telecommunications networks. In response to a handoverfailure between cells of the network, the systems and methods determinechanges have been made to a network, such as changes to variousidentification information for cells associated with a controlling (orserving) node of the network. For example, the systems and methodsutilize ANR functions to detect the changes to the network.

Once the changes have been detected, the systems and methodsautomatically modify a neighbor relations table (NRT) of the controllingnode with the new, changed, or modified information. Thus, futurehandover procedures to or using the changed cells will operatesuccessfully. The network, therefore, utilizes Self Optimizing Network(SON) procedures, such as ANR functions, to diagnose and identifychanges previously made to the network, and updates associated neighborrelation tables with the identified changes to ensure the networkmaintains a high quality of performance for handovers between cells,despite ongoing changes to the network.

In some embodiments, a controlling node of a telecommunications networkreceives an indication of an occurrence of a failure during preparationof a handover for user equipment from a source cell of thetelecommunications network to a target cell of the telecommunicationsnetwork. The node detects, using an automatic neighbor relation (ANR)function of the controlling node, one or more changes to thetelecommunications network, such as a change to a cell identifier forthe target cell. Using the detected change, the node modifies a celldefinition for the target cell within a neighbor relations table (NRT)of the controlling node using the changed cell identifier detected bythe automatic neighbor relation function.

For example, an eNodeB element of a Long Term Evolution (LTE) networkmay include components configured to perform such processes. The eNodeBmay include a handover failure module that accesses an indication of anoccurrence of a failure during preparation of a handover for userequipment from a source cell of the LTE network to a target cell of theLTE network. Further, the eNodeB may include a network changes modulethat detects, using a self-organizing network (SON) process (or otherANR process) launched by an automatic neighbor relation (ANR) functionof the eNodeB element, one or more changes to the target cell of the LTEnetwork. Also, the eNodeB element includes a table modification modulethat modifies a cell definition for the target cell within a neighborrelations table (NRT) of the eNodeB element based on the changes to thetarget cell detected by the self-organizing network (SON) process.

Thus, in some embodiments, the systems and methods facilitate thedynamic and automatic modification of cell definition tables (e.g.,NRTs) within a telecommunications network, in order to harmonize thecell definition tables to ongoing changes (inadvertent, or otherwise) tothe cells of the network. In doing so, the systems and methods avoidhandover failures between cells due to the utilization of obsolete orerroneous identifiers for the cells, among other benefits.

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of embodiments of the present technology. It will beapparent, however, that embodiments of the present technology may bepracticed without some of these specific details.

Examples of Suitable Network Environments

As described herein, in some embodiments, the systems and methodsautomatically update neighbor relation tables (NRTs) utilized duringhandover procedures for user equipment (e.g., mobile devices, such assmart phones) between cells of a telecommunications network. FIG. 1 is ablock diagram illustrating a suitable computing environment 100 formodifying cell definition tables with telecommunications networks.

The network environment 100 includes an eNodeB element 105, which is acontrolling or serving node with a telecommunications network, such asan LTE network. The eNodeB element 105, or eNB, may be hardware,connected to the network, which communicates with various mobile devicesor handsets, such as UEs, when the devices access the network via one ormore cells.

The eNodeB element 105 includes an automatic neighbor relation (ANR)function 120. Under 3GPP, the ANR function 120 performs automaticneighbor relation (NR) functions between cells of a network, such asbetween cells associated with the eNB 105. The ANR function 120 includesa neighbor relation table (NRT) management function 125, a neighbordetection function 140, and a neighbor removal function 130.

The neighbor detection function 140 detects new neighbors within thenetwork and adds them to one or more neighbor relation tables (NRTs) 110for each of the cells within the network. The neighbor removal functionremoves outdated NRs between cells of the network based on informationprovided via a radio resource control (RRC) protocol 160 of the network.

The NRT management function 125 manages, updates, and/or modifiesinformation stored by the neighbor relation tables 110, such as NRTsassociated with a cell A, a cell B, a cell C, and/or other cells (cellN) of the network and associated with the eNodeB element 105. Forexample, the neighbor detection function 140 may determine two cells areneighbor cells, and provides instructions to the NRT management function125 to update the NRTs associated with the cells with their identityinformation, so they can be located during handover procedures formobile devices on the network.

During a device-initiated handover, the device reports a physical layeridentifier of a target cell (e.g., the cell to which the device is to behanded over) to a source cell (e.g., the currently connected cell). Viathe NRT associated with the source cell (e.g., NRT for cell A), theeNodeB element 105 translates the physical layer identifier to targetcell information (TCI) for the target cell. The eNodeB element 105 thenutilizes the TCI of the target cell to request, prepare, and execute thehandover to the target cell.

Within the eNodeB element 105, the ANR functionality 120 maintains,updates, and removes neighbor cell relations (NRs) between cells. Withinthe ANR 120, a neighbor cell relation between a source cell and aneighbor cell exists when the ANR knows certain identity informationabout a target cell: (a) in LTE networks the ECGI (enhanced cell globalidentity, which is the public land mobile network PLMN) ID plus the CellIdentity of the target cell; (b) in UTRAN networks the PLMN ID, CellIdentifier (C-ID), and/or resource network controller (RNC) ID/orExtended RNC ID; and (c) in GSM networks the PLMN ID, the LAC (locationarea code), CI (cell identity), or BSIC (base station identity code).

Further, the neighbor cell relation between a source cell and a neighborcell exists when there is an entry in the neighbor relation table (e.g.,cell A of NRTs 110) for the source cell identifying the neighbor cell,and where attributes are defined in the entry of the NRT. The attributesmay include frequency information (e.g., UARFCN (UTRA Absolute RadioFrequency Channel Number), BCCH ARFCN (Broadcast Control ChannelAbsolute Radio Frequency Channel Number, or EARFCN (Evolved AbsoluteRadio Frequency Channel Number)), and/or various handover routingparameters, such as LAC and/or RAC in UTRAN networks, and TAI (trackingarea identity) information in LTE networks.

For each neighbor relation of the NRT, the entry will include the targetcell identifier (TCI), which identifies the neighbor cells (e.g., aUTRAN, LTE or GSM cell).

Thus, maintaining accurate and updated information associated with cellsof a network enables the NRTs 110 to perform accurate and reliabletranslations of cell identifiers during handover procedures. The systemsand methods, therefore, provide, via the eNodeB element 105, a tablemodification system 150 configured to modify the information stored inthe NRTs 110 for the cells of the network. In some cases, the system 150may be part of the eNodeB element 105. In other cases, the system 150may be accessible to the eNodeB element 105, such as via the ANRfunction 120.

In some cases, the table modification system 150 receives from anOperations and Management (O&M) component 170 various networkinformation, such as network statistics associated with networkperformance, event management actions, and so on. Further detailsregarding the performance or functionality of the table modificationsystem 150 are described herein.

FIG. 1 and the discussion herein provide a brief, general description ofa suitable computing environment in which the eNodeB element 105 orother components can be supported and implemented. Although notrequired, aspects of the various components or systems are described inthe general context of computer-executable instructions, such asroutines executed by a general-purpose computer, e.g., mobile device, aserver computer, or personal computer. The system can be practiced withother communications, data processing, or computer systemconfigurations, including: Internet appliances, hand-held devices(including tablet computers and/or personal digital assistants (PDAs)),all manner of cellular or mobile phones, multi-processor systems,microprocessor-based or programmable consumer electronics, set-topboxes, network PCs, mini-computers, mainframe computers, and the like.Indeed, the terms “computer,” “host,” and “host computer,” and “mobiledevice” and “handset” are generally used interchangeably herein, andrefer to any of the above devices and systems, as well as any dataprocessor.

Aspects of the system can be embodied in a special purpose computingdevice or data processor that is specifically programmed, configured, orconstructed to perform one or more of the computer-executableinstructions explained in detail herein. Aspects of the system may alsobe practiced in distributed computing environments where tasks ormodules are performed by remote processing devices, which are linkedthrough a communications network, such as a Local Area Network (LAN),Wide Area Network (WAN), or the Internet. In a distributed computingenvironment, program modules may be located in both local and remotememory storage devices.

Aspects of the system may be stored or distributed on computer-readablemedia (e.g., physical and/or tangible non-transitory computer-readablestorage media), including magnetically or optically readable computerdiscs, hard-wired or preprogrammed chips (e.g., EEPROM semiconductorchips), nanotechnology memory, or other data storage media. Indeed,computer implemented instructions, data structures, screen displays, andother data under aspects of the system may be distributed over theInternet or over other networks (including wireless networks), on apropagated signal on a propagation medium (e.g., an electromagneticwave(s), a sound wave, etc.) over a period of time, or they may beprovided on any analog or digital network (packet switched, circuitswitched, or other scheme). Portions of the system may reside on aserver computer, while corresponding portions may reside on a clientcomputer such as a mobile or portable device, and thus, while certainhardware platforms are described herein, aspects of the system areequally applicable to nodes on a network. In an alternative embodiment,the mobile device or portable device may represent the server portion,while the server may represent the client portion.

In some embodiments, the devices may include network communicationcomponents that enable the devices to communicate with remote servers orother portable electronic devices by transmitting and receiving wirelesssignals using a licensed, semi-licensed, or unlicensed spectrum overcommunications networks. In some cases, the telecommunication networkmay be comprised of multiple networks, even multiple heterogeneousnetworks, such as one or more border networks, voice networks, broadbandnetworks, service provider networks, Internet Service Provider (ISP)networks, and/or Public Switched Telephone Networks (PSTNs),interconnected via gateways operable to facilitate communicationsbetween and among the various networks. The communications network mayalso include third-party communications networks such as a Global Systemfor Mobile (GSM) mobile communications network, a code/time divisionmultiple access (CDMA/TDMA) mobile communications network, a 3rd or 4thgeneration (3G/4G) mobile communications network (e.g., General PacketRadio Service (GPRS/EGPRS)), Enhanced Data rates for GSM Evolution(EDGE), Universal Mobile Telecommunications System (UMTS), or Long TermEvolution (LTE) network), 5G mobile communications network, IEEE 802.11(WiFi), or other 3GPP or non-3GPP communications networks.

Examples of Modifying Cell Definition Tables within Networks

As described herein, in some embodiments, a handover procedure for amobile device and between a source cell and a target cell fails. Beforethe handover procedure, the TCI or another cell identifier of the targetcell may have previously changed during various network processes, suchas previously performed network optimization processes. For example, inLTE networks, the eNodeB ID or local cell ID may change for the cell, inUMTS networks, the Cell ID, LAC, RAC, or RNC may change for the cell,and for GERAN networks, the Cell ID or LAC may change for the cell.Examples of other changed identifiers or other parameters are describedherein.

The table modification system 150, however, utilizes the ANR function120 to detect the changes to the network, and modify neighbor relationtables associated with the target cell to include the changedinformation. Thus, future handover procedures between the cells willsucceed, enhancing the performance of the network, despite continuouschanges being made to the network.

FIG. 2 is a block diagram illustrating various modules of the tablemodification system 150. The table modification system 150 includesfunctional modules or engines that are implemented with a combination ofsoftware (e.g., executable instructions, or computer code) and hardware(e.g., at least a memory and processor). Accordingly, as used herein, insome examples a module or engine is a processor-implemented module orset of code and represents a computing device having a processor that isat least temporarily configured and/or programmed by executableinstructions stored in memory to perform one or more of the particularfunctions that are described herein. For example, the table modificationsystem 150 may include a handover failure module 210, a network changesmodule 220, and a table modification module 230.

In some embodiments, the handover failure module 210 is configuredand/or programmed to access an indication of an occurrence of a failureduring preparation of a handover for user equipment from a source cellof a network to a target cell of the network. For example, the handoverfailure module 210 determines a handover procedure has failed during apreparation phase of the procedure, such as during provisioning of thetarget cell using erroneous or obsolete information for the target celltranslated by the NRT 110.

In some embodiments, the network changes module 220 is configured and/orprogrammed to detect, using a self-organizing network (SON) process orother automatic neighbor relation (ANR) functionality 120 of the eNodeBelement 105, one or more changes to the target cell of the network. Forexample, the network changes module 220 identifies changed identityinformation for cells within the network.

As described herein, the ANR function 120 receives information fromcells broadcasting their identity on a global level (e.g., broadcastingtheir E-UTRAN Cell Global Identifier (ECGI) or CGI information). TheeNodeB element 105 requests that the UE (e.g., mobile devices) collectthe broadcasted information. First, the UE may send to the eNodeBelement 105 a report that includes a target cell's PCI (but not its ECGIor CGI). Upon receipt of the PCI, the eNodeB element 105 instructs theUE, using the PCI for the target cell, to identify the ECGI, the TAC,and any PLMN ID(s) for any related neighbor cells.

Once the UE determines the ECGI information for the neighbor cells, theUE sends the ECGI information to the eNodeB element 105, as well as anytracking area code (TAC) information and all detected PLMN IDs. Also,when a neighbor cell is a CSG or hybrid cell, the UE reports the CSG IDto the eNodeB element 105. Thus, the ANR function 120 operates to causethe UE to detect and provide identity information for cells within thenetwork, such as for a target cell and various neighbor cells to thetarget cell.

Of course, in non-LTE networks, other elements corresponding to theeNodeB may store the NR information and perform the functions describedherein (e.g., with respect to the eNodeB element 105). For example, inWCDMA networks, a resource network controller (RNC) includes the systemsdescribed herein, and in GSM networks, the base station controller (BSC)includes the systems described herein.

In some embodiments, the table modification module 230 is configuredand/or programmed to modify a cell definition for the target cell withina neighbor relations table (NRT) 110 of the eNodeB element 105 based onthe changes to the target cell detected by the ANR functionality 120.For example, the table modification module 230 causes the NRT managementfunction 125 to access and modify an NRT associated with the target cellwith the updated information for the cell.

As described herein, the table modification system 150 may performvarious processes, routines, or algorithms when automatically updatingneighbor relation tables for cells of a network. FIG. 3 is a flowdiagram illustrating a method 300 for modifying cell definition tablesfor a telecommunications network. The method 300 may be performed by thetable modification system 150 and, accordingly, is described hereinmerely by way of reference thereto. It will be appreciated that themethod 300 may be performed on any suitable hardware.

In operation 310, the table modification system 150 determines there isa failure during preparation of handover of user equipment from a sourcecell to a target cell. The system 150 could determine the handoverpreparation failure, for example, by receiving an indication of anoccurrence of a failure during preparation of a handover for userequipment from a source cell of the telecommunications network to atarget cell of the telecommunications network. For example, the handoverfailure module 210 may determine a handover procedure has failed duringa preparation phase of the procedure (e.g., a source eNodeB receives a“cell not available” radio layer message from the target eNodeB), suchas during provisioning of the target cell using erroneous or obsoleteinformation for the target cell translated by the NRT 110. Suchinformation may be received from the UE.

In operation 320, the system 150 detects, during one or more SONprocesses (e.g., an automatic neighbor relation (ANR) function of thecontrolling node), one or more changes to the telecommunicationsnetwork. For example, the network changes module 220 identifies changedidentity information for cells within the network, such as changes to acell identifier for the target cell.

As described herein, the system 150 may detect various changes to cellsof a network, including one or more changes to a physical layeridentifier for the target cell, one or more changes to cell identityinformation for the target cell, one or more changes to target cellidentifier (TCI) information for the target cell, and other informationdescribed herein.

In some cases, the network changes module 220 may automaticallyperforming a self-organizing network (SON) process to determine the oneor more changes to the telecommunications network, such as in responseto the received indication of the occurrence of the handover preparationfailure.

In operation 330, the system 150 modifies a cell definition for thetarget cell within a neighbor relations table (NRT) of the controllingnode using the changed cell identifier detected by the automaticneighbor relation function. For example, the table modification module230 causes the NRT management function 125 to access and modify an NRTassociated with the target cell with the updated information for thecell.

As described herein, the system 150 may modify various informationcontained in the NRTs 110 for a given cell. The system 150 may modifyand/or broadcast the TCI information for the cell, such as controlchannel (BCCH) information, primary scrambling code (PSC) information,or physical cell identity (PCI) information for the target cell withinthe neighbor relations table of the controlling node.

As described herein, the table modification system 150 utilizes ANR andother SON processes to detect changes to cell identifiers for cellswithin a network and update associated neighbor relation tables 110 toreflect the changes within the network. FIG. 4 is a flow diagramillustrating a method 400 for determining changes to atelecommunications network using automatic neighbor relation (ANR)functionality. The method 400 may be performed by the table modificationsystem 150 and, accordingly, is described herein merely by way ofreference thereto. It will be appreciated that the method 400 may beperformed on any suitable hardware.

In operation 410, a PCI is reported to the eNodeB element 105 by the UEduring a handover request to a target cell. In operation 420, the system150 determines whether a neighbor relation exists for the PCI. When theneighbor relation does exist, the method 400 proceeds to operation 430,and initiates a handover preparation procedure. When there is no NR, thesystem 150, in operation 425, via an ANR process, requests the UE toreport a CGI for the target cell, and the eNodeB element 105 builds aneighbor relation for the cell.

In operation 440, the system 150 determines whether the handoverprocedure fails during preparation. When the handover preparation doesnot fail, the UE, in operation 445, executes handover to the targetcell, and commences communication over the network via the target cell.

When the handover preparation fails, the system 150 proceeds tooperation 450, and determines whether the failure is due to nonexistentCGI information in the NR (e.g., where CGI information is stored in theNR for a nonexistent cell). For example, the system 150 may determinefrom failure messages sent between a source cell eNodeB and a targetcell eNodeB (or other similar elements in other networks), that notarget cell exists, the CGI information for the target cell is invalid,the preparation has expired, and so on.

When the failure is not due to the lack of CGI information, the method400, in operation 480, ends the current routine, and informs the networkof the handover failure. When the failure is due to the lack of CGIinformation (or other incorrect CGI information contained in the NR),the method 400 proceeds to operation 455, and determines CGI informationfor the target cell.

After obtaining the CGI information for the target cell, the method 400proceeds to operation 460, and using the SON processes to determine ifthere are additional constraints to be imposed to reduce the determinederrors. For example, the SON may impose an additional constraint ofdistance (e.g., the cell being <Xkm away), tier of the target, or someother restriction (e.g., disallowing handover when the target has ahistorical high failure rate from other cells in the network), andreduce errors by imposing such constraints.

Absent any additional constraints, the method 400, in operation 465,initiates handover preparation using the obtained CGI information.

In operation 470, the method 400 determines whether the handoverpreparation is successful (handover is prepared and, later, isexecuted). Once successful, the method 400, in operation 475, modifiesthe NR tables with the CGI information (associated with the successfulhandover execution), else the method 400 proceeds to operation 425, andrequests new CGI information.

As an example, a handover is attempted between an LTE source cell and anLTE target cell. Following the systems and methods described herein, theANR may utilize (MCC-MNC-eNBID-CIDx)+PCI+frequency information, and ifthe system determines one or more CID variations caused the failure(e.g., the CID changed as part of a previous network optimizationprocess), the system executes the handover to CIDy (based on theobtained CGI information), and modifies the cell definition table forfuture handovers (verified later by SON processes).

As another example, a handover is attempted between an LTE source celland a WCDMA or GSM target cell. Following the systems and methodsdescribed herein, the ANR may utilize (MCC-MNC-LACy/RACzCIDa)+PCI+frequency+other identifiers, and if the system determines oneor more identifiers (e.g., CID or LAC or RAC) and/or associatedvariation caused the failure (e.g., the CID/LAC/RAC changed as part of aprevious network optimization process), then the system prepares thehandover to (MCC-MNC-LACb/RACc CIDd) and modifies the cell definitiontable for future handovers (verified later by SON processes).

Thus, in some embodiments, the systems and methods utilize the ANRfunctionality via SON processes of a controlling or serving node of anetwork to identify changes to cells that result in handover failuresbetween the cells. The systems and methods then update neighborrelations tables with the identified changes, to prevent future handoverfailures between the cells. The systems and methods, therefore, maintainaccurate and/or optimized neighbor relations tables for a group of cellswhile the cells (and their associated network) continuously changes,among other benefits.

CONCLUSION

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” As used herein, the terms “connected,”“coupled,” or any variant thereof means any connection or coupling,either direct or indirect, between two or more elements; the coupling orconnection between the elements can be physical, logical, or acombination thereof. Additionally, the words “herein,” “above,” “below,”and words of similar import, when used in this application, refer tothis application as a whole and not to any particular portions of thisapplication. Where the context permits, words in the above DetailedDescription using the singular or plural number may also include theplural or singular number respectively. The word “or,” in reference to alist of two or more items, covers all of the following interpretationsof the word: any of the items in the list, all of the items in the list,and any combination of the items in the list.

As used herein, being above a threshold means that a value for an itemunder comparison is above a specified other value, that an item undercomparison is among a certain specified number of items with the largestvalue, or that an item under comparison has a value within a specifiedtop percentage value. As used herein, being below a threshold means thata value for an item under comparison is below a specified other value,that an item under comparison is among a certain specified number ofitems with the smallest value, or that an item under comparison has avalue within a specified bottom percentage value. As used herein, beingwithin a threshold means that a value for an item under comparison isbetween two specified other values, that an item under comparison isamong a middle specified number of items, or that an item undercomparison has a value within a middle specified percentage range.

The above Detailed Description of examples of the technology is notintended to be exhaustive or to limit the technology to the precise formdisclosed above. While specific examples for the technology aredescribed above for illustrative purposes, various equivalentmodifications are possible within the scope of the technology. Forexample, while processes or blocks are presented in a given order,alternative implementations may perform routines having steps, or employsystems having blocks, in a different order, and some processes orblocks may be deleted, moved, added, subdivided, combined, and/ormodified to provide alternative or subcombinations. Each of theseprocesses or blocks may be implemented in a variety of different ways.Also, while processes or blocks are at times shown as being performed inseries, these processes or blocks may instead be performed orimplemented in parallel, or may be performed at different times. Furtherany specific numbers noted herein are only examples: alternativeimplementations may employ differing values or ranges.

The teachings of the technology provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various examples described above can be combined to providefurther implementations of the technology. Some alternativeimplementations of the technology may include not only additionalelements to those implementations noted above, but also may includefewer elements.

These and other changes can be made to the technology in light of theabove Detailed Description. While the above description describescertain examples of the technology, and describes the best modecontemplated, no matter how detailed the above appears in text, thetechnology can be practiced in many ways. Details of the system may varyconsiderably in its specific implementation, while still beingencompassed by the technology disclosed herein. As noted above,particular terminology used when describing certain features or aspectsof the technology should not be taken to imply that the terminology isbeing redefined herein to be restricted to any specific characteristics,features, or aspects of the technology with which that terminology isassociated. In general, the terms used in the following claims shouldnot be construed to limit the technology to the specific examplesdisclosed in the specification, unless the above Detailed Descriptionsection explicitly defines such terms. Accordingly, the actual scope ofthe technology encompasses not only the disclosed examples, but also allequivalent ways of practicing or implementing the technology under theclaims.

To reduce the number of claims, certain aspects of the technology arepresented below in certain claim forms, but the applicant contemplatesthe various aspects of the technology in any number of claim forms. Forexample, while only one aspect of the technology is recited as acomputer-readable medium claim, other aspects may likewise be embodiedas a computer-readable medium claim, or in other forms, such as beingembodied in a means-plus-function claim. Any claims intended to betreated under 35 U.S.C. § 112(f) will begin with the words “means for”,but use of the term “for” in any other context is not intended to invoketreatment under 35 U.S.C. § 112(f). Accordingly, the applicant reservesthe right to pursue additional claims after filing this application topursue such additional claim forms, in either this application or in acontinuing application.

What is claimed is:
 1. A method performed by a controlling node of atelecommunications network, the method comprising: receiving anindication of a handover preparation failure during preparation of ahandover for user equipment from a source cell of the telecommunicationsnetwork to a target cell of the telecommunications network; in responseto receiving the indication of the handover preparation failure duringpreparation of the handover, detecting, using an automatic neighborrelation (ANR) function of the controlling node, one or more changes tothe telecommunications network, wherein the one or more changes includeat least one change to a cell identifier for the target cell; andmodifying a cell definition for the target cell within a neighborrelations table (NRT) of the controlling node using the changed cellidentifier detected by the automatic neighbor relation function.
 2. Themethod of claim 1, wherein the automatic neighbor relation (ANR)function is part of a self organizing network (SON) process thatdetermines the one or more changes to the telecommunications network,wherein the controlling node automatically performs the SON process inresponse to the received indication of the handover preparation failure.3. The method of claim 1, wherein the telecommunications network is aLong Term Evolution (LTE) radio access network, and the controlling nodeis an eNodeB element of the LTE network.
 4. The method of claim 1,wherein the one or more changes to the cell identifier for the targetcell include changes to one or more physical layer identifiers for thetarget cell.
 5. The method of claim 1, wherein the one or more changesto the cell identifier for the target cell include a change to cellidentity information for the target cell.
 6. The method of claim 1,wherein the one or more changes to the cell identifier for the targetcell include a change to target cell identifier (TCI) information forthe target cell.
 7. The method of claim 1, wherein modifying the celldefinition for the target cell within a neighbor relations table (NRT)of the controlling node includes modifying, using a NRT managementfunction component of the controlling node, broadcast control channel(BCCH) information, primary scrambling code (PSC) information, orphysical cell identity (PCI) information for the target cell within theneighbor relations table of the controlling node.
 8. The method of claim1, wherein modifying the cell definition for the target cell within aneighbor relations table (NRT) of the controlling node includesmodifying, using a NRT management function component of the controllingnode, cell global identity (CGI) information or enhanced cell globalidentity (ECGI) information for the target cell within the neighborrelations table.
 9. The method of claim 1, wherein receiving anindication of an occurrence of a failure during preparation of ahandover includes receiving the indication of the handover preparationfailure from the user equipment.
 10. A non-transitory computer-readablemedium whose contents, when executed by a controlling node of atelecommunications network, cause the controlling node to performoperations, the operations comprising: receiving an indication of ahandover preparation failure during preparation of a handover for userequipment from a source cell of the telecommunications network to atarget cell of the telecommunications network; in response to receivingthe indication of the handover preparation failure during preparation ofthe handover, detecting, using an automatic neighbor relation (ANR)function of the controlling node, one or more changes to thetelecommunications network, wherein the one or more changes include atleast one change to a cell identifier for the target cell; and modifyinga cell definition for the target cell within a neighbor relations table(NRT) of the controlling node using the changed cell identifier detectedby the automatic neighbor relation function.
 11. The non-transitorycomputer-readable medium of claim 10, wherein detecting one or morechanges to the telecommunications network includes automaticallyperforming a self organizing network (SON) process to determine the oneor more changes to the telecommunications network, wherein thecontrolling node automatically performs the SON process in response tothe received indication of the handover preparation failure.
 12. Thenon-transitory computer-readable medium of claim 10, wherein thetelecommunications network is a Long Term Evolution (LTE) radio accessnetwork, and the controlling node is an eNodeB element of the LTEnetwork.
 13. The non-transitory computer-readable medium of claim 10,wherein the one or more changes to the cell identifier for the targetcell include a change to a physical layer identifier for the targetcell.
 14. The non-transitory computer-readable medium of claim 10,wherein the one or more changes to the cell identifier for the targetcell include a change to cell identity information for the target cell.15. The non-transitory computer-readable medium of claim 10, wherein theone or more changes to the cell identifier for the target cell include achange to target cell identifier (TCI) information for the target cell.16. The non-transitory computer-readable medium of claim 10, whereinmodifying the cell definition for the target cell within a neighborrelations table (NRT) of the controlling node includes modifying, usinga NRT management function component of the controlling node, broadcastcontrol channel (BCCH) information, primary scrambling code (PSC)information, or physical cell identity (PCI) information for the targetcell within the neighbor relations table of the controlling node. 17.The non-transitory computer-readable medium of claim 10, whereinmodifying the cell definition for the target cell within a neighborrelations table (NRT) of the controlling node includes modifying, usinga NRT management function component of the controlling node, cell globalidentity (CGI) information or enhanced cell global identity (ECGI)information for the target cell within the neighbor relations table. 18.The non-transitory computer-readable medium of claim 10, whereinreceiving an indication of an occurrence of a failure during preparationof a handover includes receiving the indication of the handoverpreparation failure from the user equipment.
 19. A system, comprising:an eNodeB element of a Long Term Evolution (LTE) network, wherein theeNodeB element is configured to execute software modules, including: ahandover failure module that accesses an indication of a handoverpreparation failure during preparation of a handover for user equipmentfrom a source cell of the LTE network to a target cell of the LTEnetwork; a network changes module that detects, using a self-organizingnetwork (SON) process, one or more changes to the target cell of the LTEnetwork in response to receiving the indication of the handoverpreparation failure during preparation of the handover; and a tablemodification module that modifies a cell definition for the target cellwithin a neighbor relations table (NRT) of the eNodeB element based onthe changes to the target cell detected by the self-organizing network(SON) process.
 20. The system of claim 19, wherein the tablemodification module modifies the cell definition for the target cellwith cell global identity (CGI) information or enhanced cell globalidentity (ECGI) information identified by the network changes module.